Examples of the explosive material include a military explosive material used as a chemical weapon (e.g., artillery shells, bomb, land mine, or underwater mine). Such a military explosive material includes, for example, a steel shell, a bursting charge contained in the shell, and a chemical agent harmful to humans. Examples of the chemical agent include mustard gas and lewisite harmful to humans.
Blasting treatment is known as a method for disposing of the explosive material (e.g., method for making the explosive material harmless). The blasting treatment, which does not involve any disassembling operation, is suitable for disposing of not only explosive materials preserved in good condition, but also those hard to disassemble due to deterioration over time and deformation. The blasting treatment is often performed inside a hermetically-sealed pressure vessel. This is to prevent a chemical agent from leaking out, or to reduce environmental impacts, such as noise and vibration, caused by the blasting.
However, the blasting treatment may not be able to fully destroy the shell of the explosive material. As a result, after the blasting treatment, a chemical agent harmful to humans may remain inside the pressure vessel.
As a solution to this, for example, a residue may be neutralized by an agent or, as disclosed in Patent Literature (PTL) 1, a cleaning explosive may be exploded to decompose a residue using the explosive energy.
In the method of neutralizing the residue, the neutralization takes time depending on the type of residue. To neutralize different types of residue, the neutralization needs to be performed multiple times and requires a long time for the treatment. In the method of decomposing the residue by exploding the cleaning explosive, where different types of residue are simultaneously decomposed by shock waves and gas of very high temperature generated by the explosion, it is possible to reduce the time required for the treatment. However, depending on the chemical agent or the like contained in the explosive material, substances that cannot be decomposed by the shock waves and high-temperature gas may be contained in the residue. As a result, the residue may adhere, as rust or the like, to an inner wall surface of the pressure vessel. If the residue adheres to the inner wall surface of the pressure vessel, the operator has to scrape off the adhering substances. This means that it is not possible to achieve a full reduction in processing time.